Dummy bar handling mechanism



United States Patent Inventors Appl. No.

Filed Patented Assignee Irving Roost Morristown;

Horst lluber, Roselle Park; Herbert Fletert, Wycltofl, New Jersey 692,219

Dec. 20, 1967 Nov. 24, 1970 Concnt Incorporated vNew York, New York DUMMY BAR HANDLING MECHANISM 7 Claims, 4 Drawing Figs.

11.8. CI. 164/274, M 164/282 Int. Cl. 822d 1 1/08 Field of Search 164/82, 274, 282, 283; l98/Inq; l93llnq 226/lnq References Cited UNITED STATES PATENTS 3.338.297 8/1967 Foldessy 3,351,124 11/1961 Hess 3,426,835 2/1969 Michelson Primary Examiner-J. Howard Flint, Jr. Assistant Examiner-R. Spencer Annear v Attorney-Sandoe, Neill, Schottler & Wikstrom ABSTRACT: In a continuous-casting machine for continuously casting a strand of metal whic'h emerges from the exit end of an open-ended mold whereinthe exit end of the mold is plugged by a dummy bar at the start of casting, a conduit member having two alternative conduits for a strand or dummy bar is in the path of the dummy. bar and strand from the mold and is movable to alternatively interpose one or the other of the conduits as a section of the path for moving a dummy bar on 'one of the conduits into or out of the path. In a preferred form. rolls on the path are adapted to be driven alternatively in opposite directions and are arranged to move a dummy bar from the mold to the conduit member or, by reversing the drive, from the conduit member to the mold.

iii,

Patented Nov. 24, 1970 Sheet 1 of 2 FIG.

I2 I D I DI P 25 l4 I6 22 I2 I /1,, I2 MM B 0' 29 25 A |l h ll 28 it I I 25 INVENTORS l E HERBERT FASTERT, BY HORST HUBER A TTORNEYS Patented Nov. 24, 1970 3,542,118

l N VEN TORS HERBERT FASTERT HORST HUBER 8| IRVING ROSSI A TTORNE Y5 DUMMY BAR'IIANDLING MECHANISM The present inventionrelates to machines for the continuous casting of metal and particularly to mechanism for handling dummy bars which are used in such machines.

In the operation of continuous-casting machines, molten metal is poured in one end of an open-ended mold which is cooled to solidify the periphery of the metal therein to form a strand. The strand is then withdrawn from the exit end of the mold and conducted along an appropriate path to a work station at which it is cut'into lengths and/or otherwise processed. When the strand emerges from the mold the core is still molten and, as the strand moves away from the mold, it is further cooled by suitable means such as water sprays, to prevent the core from remelting the periphery and then to complete solidification.

In some machines the strand moves down in a straight vertical line from the mold to'the first work station; in others it is conducted down along'a curved path in order'to bend it into a horizontal path where further work may be performed on it more conveniently and economically than in a vertical path. The path of the strand away from the mold is usually defined by idler rolls or other suitable support elements and the strand is customarily withdrawn from the mold by driven withdrawal rolls frictionally engaging the strand at points along the path at which the strand is sufficientlysolidified so as resist being broken or rolled out of shape by the pressure of the withdrawal rolls. v

At the start of casting, the exit end of the mold is plugged by a dummy bar until sufficient metal accumulates in the mold for a strand to form.'Then the dummy bar is withdrawn and moved down the path from the mold followed by thestrand.

In known machines the dummy bar is withdrawn from the mold with at least the assistance of the withdrawal rolls. Consequently, the dummy bar is made long enough to extend from the mold to the withdrawal rolls (or at least to the first set of them if there are more than one set) and with the withdrawal rolls positioned along a portion of the path where the strand will" be substantially solidified the dummybar must be quite long in order to reach the rolls. Thus the dummy bars as usually constituted are'cumbersome to handle and store, par

ticularly the dummy bars used in machines for casting large diameter slabs or blooms.

- An object of the-present invention is to provide mechanism for handling dummy bars that enables the use of relatively short dummy bars, as compared with dummy bars as presently constituted.

Another object isto provide means for removing a dummy bar from the path from the mold without having to travel to the end of the path, for storing it in a convenient location ready for reuse, and for reinserting it in the path in position to be moved back up the path to be plugged in the mold for a subsequent casting run.

1 A further object is to provide means for moving'the dummy from the aforesaid removal, storage and reinsertion means,

back up the path to the mold.

In accordance with a preferred form of the invention pairs of rolls, including one driven roll in each 'pair, are arranged at intervals along the portion of the path between the exit end of the mold and the conduit member for frictionally engaging a dummy bar (or strand) in the path. The first pair of these rolls is nearer the exit end of the mold than the first pair of withdrawal rolls in. known machines. Consequently, the dummy bar which is made long for one end to plug the exit end of the mold and have the other end engaged by at least the first pair of driven rolls, may be much shorter and less cumbersome than-heretofore required. The successive driven rolls along the-path to the conduit member are spaced so that the distances between them and between the upstream end of the conduit member and the first driven roll upstream from it, are each less than the length of the dummy bar. The driven rolls of these pairs are adapted to be driven alternatively in reverse directions by conventional drive connections and are thus operable to move a dummy bar in either direction along the path, for withdrawing a dummy bar from the mold and conveying it to the conduit member in one direction, and moving it in the reverse direction, from the conduit member back up the path to mold-plugging position.

The driven rolls for moving the dummy bar in accordance with this invention operate with less pressure than the usual withdrawal rolls for the strand and therefore will not distort the shape of the strand, which follows the dummy bar. Driven withdrawal rolls in the form applied in known machines are provided in the path'downstream from the conduit member to firmly engage the strand and assure its movement through the machine at a uniform rate. 7

Further objects, advantages and features of this invention will be apparent in the following description of illustrative embodiments depicted in the accompanying drawings wherein:

FIG. 1 is a side, view of a vertical section through the essential portions of a continuous-casting machine having a dummy bar handling mechanism of the present invention, showing the elements diagrammatically;

FIG. 2 is a partial view of the machine shown in FIG. 1, showing the conduit member of the mechanism in its alternative position;

FIG. 3 is a view similarto the view of FIG. 1, but showing another embodiment of dummy bar handling mechanism of this invention; and

' FIG 4 is a partial vi'ew of the embodiment illustrated in FIG. 3, showing the conduit member of FIG. 3. in its alternative position.

Referring to the drawings, FIG. 1 shows a continuous-casting machine in which an open-ended mold 10 casts a continuous strand 11 of metal which emerges from the bottom, exit, end of the mold and moves down a path defined by pairs of idler rolls 1-2 to a pair of driven withdrawal rolls 13, that firmly engage thestrand, as seen in FIG. 2, for assuring positive movement of the strand through the machine. The path defined by idler rolls l2 and withdrawal rolls 13 is shown as These and other objects are accomplished by the dummy 7 bar handling mechanism of'the present invention in which a conduit member having two conduits for the dummy bar and strand is arranged in the path for the strand from the mold to be movable to alternative positions in which one or theother of the conduits forms a section of the path. Thus, when the dummy bar is on the conduit which is in position forming a section of the path, the dummy bar is removed from the path by moving the conduit member to its alternative-position. Thus, the conduitbearing' the dummy bar moves out of the path and is replaced by the other conduit so that the pathway for the strand, which follows the dummy bar, is clear and uninterrupted. The conduit, on whichthe dummy bar then rests, provides a storage position from which the dummy bar can readily be replaced on the path, after the tail end of the strand has passed the conduit member, by moving the conduit member to switch the positions of the conduits again.

being curved in the drawing, but it could also be straight in a vertical line.

At the start of casting, a dummy bar 14, which has approximately the same cross-sectional dimensions as the strand 11, has its upstream end received in and plugging the exit end of the mold 10 until sufficient molten metal, indicated at 15, is accumulated in the mold for the strand 11 to be formed therein-Then the dummy bar is withdrawn and moves down the path defined by the rolls l2, and is followed by the strand 1 1.

In accordance with the present invention a conduit member 16 is arranged in the path for the strand-and is preferably located upstream from the withdrawal rolls l3and a sequence of driven rolls D, each paired with and spaced from a back-up roll D, are interspersed between the idler rolls 12 at spaced intervals along the portion of the path between the mold and the conduit member 16. The rolls D and D of each pair are spaced apart to permit passage of the dummy bar 14 or the strand ll between them and to frictionally engage the dummy bar 14 or strand 11 thus passing between. The distances between the mold and the first roll D in the sequence, between the rolls D, and between the conduit member 16 and the roll D upstream from it are less than the length of the dummy bar 14. The pairs of rolls D and D are thus adapted to apply power to move the dummy bar all the way along the path between the mold and conduit member, and the driven rolls D are drivingly connected in a conventional manner to a drive motor (not shown) to be selectively driven in one direction or the other for moving the dummy bar either down the path from the mold to the conduit member or in the reverse direction, from the conduit member to the mold.

The conduit member 16, as shown, has a pair of alternate conduits 20 and 21 thereon and each conduit is adapted to form a section of the path for the dummy bar 14, or strand 11, between the rollers D and D upstream from the conduit member 16 and the withdrawal rolls 13. Suitable-means, such as a hydraulically operated piston in a cylinder 22 having a reciprocating piston rod 23 pivotally connected at 24 to the frame 25 of the conduit member, is provided to move the conduit member 16 from the position shown in FIG. 1, in which the conduit 20 is in position forming a section for a through path, to the alternate position shown in FIG. 2, in which the conduit 21 is in the position to complete the path.

As illustrated, the conduit 20 is formed by a solid platform element 27 and the conduit 21 is formed .by pairs of spaced idler rolls 28 with intermediate platform segments 29. The exact form of the conduits is not critical, however, and, in FIGS. 3 and 4, both conduits 20 and 21 are shown formed by platform elements 27.

One of the conduits, conduit 20 in the embodiments illustrated, has a stop lever 30 at its downstream end connected to the frame 25 by a pivot 31 and is mounted in a conventional manner so as to be resiliently urged downward to block the downstream end of the conduit. The stop lever 30 is thus operable to block the conduit so that the dummy bar 14 moving down the path is brought to rest on the conduit 20. If it is desired to let the dummy bar proceed along the path, the stop lever 30 may be lifted up out of the way. Otherwise the stop lever holds the dummy bar 14 on the conduit 20 as shown in FIG. 1 so as to be lifted out of the path by moving the conduit member 16 to the position illustrated in FIG. 2 wherein the dummy bar 14 is stored out of the way on conduit 20 and conduit 21 provides the through path for the strand 11 which moves down the path after the dummy bar. After the tail end of the strand has moved past the conduit member, the conduit member 16 may be moved back to the former position (FIG. 1) to replace the dummy bar in the path ready to be moved back up the path to be plugged into the mold for a subsequent casting run. This latter is accomplished by reversing the drive for the rolls D and then pushing the dummy bar back off the conduit 20 into the bite of the first pair of rolls D, D' upstream from the conduit member. Means, such as a hydraulically operated piston (not shown) connected to the stop lever, is suitably provided for swinging the stop lever to the left for pushing the dummy bar 14 back. The sequence of rolls D, D' then conduct the dummy bar back up to the mold.

FIGS. 3 and 4 illustrate another form of casting machine embodying the invention. In this form one pair of idler rolls 12 is located very close to the exit end of the mold to guide the strand or dummy bar. The path is further defined by one pair of withdrawal control rolls D" of which at least one is driven. This pair of rolls of D" is nearer the exit end of the mold than the first pair of withdrawal control rolls in known machines. This in turn permits the use of a very short dummy bar, since the dummy bar now has only to have the length of the distance between the pair ofwithdrawal control rolls D" and the mold. The shortness of this dummy bar results in a low weight and easy-to-handle dummy bar, and therefore only a comparatively low pressure has to be applied by the withdrawal control rolls D" on the dummy bar and subsequently on the following strand.

In this embodiment the conduit member 16 is positioned below the rolls D" a distance less than the length of the dummy bar in order forthe rolls D" to operate to move a dummy bar from the conduit 20 of the conduit member, back up to the mold by movement of stop lever 30, which is operated to push a dummy bar off the conduit 20 as described with reference to the embodiment shown in FIGS. 1 and 2, and by reversing the drive of the rolls D".

From the conduit member 16 a strand moving down from the mold is suitably conducted along acurved path to the withdrawal or forwarding rolls 13 by a chute 35.

As indicated by the two positions of the conduit member 16 shown in FIGS. 3 and 4 the operation of the mechanisms of these Figures is the same as the operation of the mechanism described with reference to the machine illustrated in FIGS. 1 and 2.

While the mechanism of this invention is shown as applied to a casting machine in which the strand 11 is conducted from the mold 10 along a curved path, it will be appreciated that it is also suited for machines in which the strand moves down a straight path, and that the conduit member 16 may be placed along a curved, vertical or straight section of the path.

It is also to be understood that the embodiments of the invention shown in the drawings and described in detail above are illustrative only and that some modifications and variations may be made in the structure and mode of operation thereof without departing from the scope of the invention defined by the following claims.

We claim:

1. In a continuous-casting machine wherein a strand of metal is formed in an open-ended mold and emerges from an exit end thereof, and wherein a dummy bar is applied to plug said exit end at the start of casting and is thereafter withdrawn, the improvement comprising a path for conducting the dummy bar and strand away from the exit end of the mold, a member in said path having a pair of conduits therethrough for the dummy bar and the strand, each of said conduits being a sufficient length to support the dummy bar, and means for selectively moving the member to alternative positions in which one or the otherof the conduits constitutes a section of said path, whereby a dummy bar on one of the conduits is placed in the path and removed therefrom by moving the member from one of said positions to the other.

2. The machine of claim 1 including stop means on one of said conduits for preventing a dummy bar on said conduit from moving further in the downstream direction of the path.

5 3. The machine of claim 2 in which said stop means is pivotally mounted for pushing a dummy bar, which is against it, in an upstream direction.

4. The machine of claim 1 in which the path includes a pair of rolls between the exit end of the mold and said member, said rolls being spaced apart and arranged for engaging respectively opposite sides of a strand or dummy bar on the path and at least one of the rolls being a driven roll, and in which the distances between the exit end of the mold and said rolls and between said rolls and said member are each less than the length of the dummyv bar whereby the rolls are adapted for drivingly moving a dummy bar from the mold to the member.

5. The machine of claim 4 in which said pair of rolls is adapted to be driven alternatively in opposite directions for moving a dummy bar down the path from the mold to said member when the pair of rolls is driven in one direction and up the path from the member'to the mold when it is driven in the reverse direction.

6. The machine of claim 1 which includes a sequence of pairs of rolls along the path between the exit end of the mold and said member, the rolls in each pair including a driven roll and being spaced apart and arranged for engaging respectively opposite sides of a strand or dummy bar on the path, and in which the distances between adjacent pairs of the rolls, between the exit end of the mold and the first pair of rolls in the sequence and between said member and the last pairin the sequence are each lessithan the length of the dummy bar whereby the rolls are'adapted for drivingly moving a dummy bar from the mold to the member.

7. The machine of claim 6 in which said driven rolls are each adapted to be driven alternatively-in opposite directions Q for moving a dummy bar down the path from the mold to said reverse direction. 

